Aquarion claims its zero liquid system as lowest cost
Process industry water systems and technology firm, Aquarion Group, has unveiled its zero liquid discharge (ZLD) system which it claims brings significant operating and capital cost savings making it the "lowest cost ZLD system available".The ZLD.eco2 process uses a series of innovative filtration and separation technologies to reduce the subsequent evaporation of residual waste products to a minimum and lower energy requirements. The system's modular design also reduces the plant footprint.
"We believe that ZLD.eco2 is the lowest cost ZLD system available today," said Aquarion chief executive officer, Karl Michael Millauer.
ZLD.eco2 requires about 20% less energy than conventional systems without pre- concentration according to Aquarion. The evaporation system is small and so requires as much as 80% less cooling energy for the condensation process the manufacturer said. The modular construction of the system can reduce staffing by around 20%, while commissioning costs are also lower by 20% while reduced consumption of chemicals is brought further cost reductions Aquarion said. "Thanks to savings on different levels, investments in ZLD.eco2 have a very short payback period," the company added.
At the heart of the system is a high-pressure reverse osmosis stage that utilizes Circular Disc (CD) Module technology developed by Aquarion subsidiary, Membran Filtrations Technik (MFT). ZLD.eco2 involves a pre-treatment process, which can either be chemical-physical or biological depending on the user, and an ultra-filtration stage to remove residual organic material, followed by multi-stage membrane technology designed to concentrate non-organic waste material.
After the first two reverse osmosis stages entailing pressures of up to 80 bar, the residual concentrate contains around 20% of the total waste water volume. This is then subjected to a third reverse osmosis stage where pressures of up 200 bar are reached. This stage uses MFT's CD module through which water takes a circular path, thereby reducing pressure losses.
The high pressure warms the concentrate to about 70°C. This is then vaporized in the subsequent low pressure stage, which acts with the membrane technology to form a hybrid thermal/ membrane system, giving the concentrate a manageable consistency. The thermal energy is fed back into the system and used to increase energy efficiency. T
"The volume of waste products still present after the maximum pre-concentration produced by the high-pressure membrane technology is significantly lower than with conventional processes. As a result, the evaporation stage with ZLD.eco2 can be considerably shorter, " claimed Aquarion.
The Circular Disc Modules are available from MFT, and ZLD.eco2 systems are available through Hager+Elsaesser (H+E), another Aquarion Group company.